HP ProBook 4510s power problem

[meritosari]

Re: HP ProBook 4510s power problem

a little make a confuse pin#5 of LM393 connected to pin#7 through resistor R33 1MOhm, but pin#7 value is 19v. pin#8 shorted to pin#7?

[meritosari]

Re: HP ProBook 4510s power problem

i've got boardview but is different for your work

open it with place5-f2b
http://laptopserviz.bg/media/wysiwyg/place5-F2B.rar

[rtstorm]

Re: HP ProBook 4510s power problem

on U1004 pin #7 is 19V but pin#5 is 5V.

The boardview is different so i cannot use it

[rtstorm]

Re: HP ProBook 4510s power problem

i try to remove Q1018 and i still have 19V on pin#4 of Q25. So i think this resistor (R1072) is issue? But i cannot find him.

[rtstorm]

Re: HP ProBook 4510s power problem

i fount that resistor. It is 220 kOhm and Capactior is ok.
On one side of resistor i have 19.9V and other is 19.4V

[rtstorm]

Re: HP ProBook 4510s power problem

i try to remove R1072 and now i have 3.8V on pin#4 of Q25. I managed to start laptop by measuring voltage from pin#4 of Q25 and GND and laptop start working. But when i want to start i must use multimeter.

[rtstorm]

Re: HP ProBook 4510s power problem

i does make any sense to me. When i remove resistor i have 3.8V on Q25 pin#4 and with resistor i have 19V.

Resistor is ok (220kOhm) and cap is 100nF (0.1uF)

[meritosari]

Re: HP ProBook 4510s power problem

consider try replacing q1018 as samanthban said, and see what result

[meritosari]

Re: HP ProBook 4510s power problem

see... and measure on LM393 pin#7 to clearing situation

[rtstorm]

Re: HP ProBook 4510s power problem

pin#7 of LM393 (U1004) is 19V.

when i remove the resistor i have 3.8V on Q26 pin#4

[meritosari]

Re: HP ProBook 4510s power problem

pin#7 of LM393 (U1004) is 19V.

when i remove the resistor i have 3.8V on Q26 pin#4

when you remove R1072, what voltage pin#7 LM393 still 19v?

i think it should be 7-9v to send adp_en# to pass through Q1018, and make pin#4 to switch Q25

can you power on with battery only?

[rtstorm]

Re: HP ProBook 4510s power problem

when i remove R1072 pin#7 of LM393 is still 19v.

I do not have battery

[rtstorm]

Re: HP ProBook 4510s power problem

when i measure voltage on this rail i instantly get drop from 19V to 3V and then i can power up the laptop. And i can power up many times until u disconect power supply.

[rtstorm]

Re: HP ProBook 4510s power problem

can i just short the resistor R1072? And leave it in that way?

[rtstorm]

Re: HP ProBook 4510s power problem

It did not work to just short the resistor.

[rtstorm]

Re: HP ProBook 4510s power problem

on U1004 i have 56 kOhm between pin#5 and pin#7. i think this should be higher resistance

[rtstorm]

Re: HP ProBook 4510s power problem

i managed to fix it, i replace resistor R29. It was broken. Thank you meritosari for help.

[meritosari]

Re: HP ProBook 4510s power problem

nice job.

[usman14]

Re: HP ProBook 4510s power problem

i have an hp probook 4510s and its power jack blue light blinking continuously

[usman14]

Re: HP ProBook 4510s power problem

i have an hp probook 4510s and its power jack blue light blinking continuously.and does not power on plz any one help me